What do you need to know and what do you plan running it on? Do you know anythign about how it was used before. If you’re on Facebook (name seems familiar), lookup the “Proper karting” group. Lots of 100cc head there, including me.
If its been converted to run alky on an oval then that changes things a little. Do you have pics?

100VM was 95-97 homologation for the ICA class. It should have a large square aluminum jacket around the barrel.